/*
* PTP 1588 clock using the IXP46X
*
* Copyright (C) 2010 OMICRON electronics GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ptp_clock_kernel.h>
#include <mach/ixp46x_ts.h>
#define DRIVER "ptp_ixp46x"
#define N_EXT_TS 2
#define MASTER_GPIO 8
#define MASTER_IRQ 25
#define SLAVE_GPIO 7
#define SLAVE_IRQ 24
struct ixp_clock {
struct ixp46x_ts_regs *regs;
struct ptp_clock *ptp_clock;
struct ptp_clock_info caps;
int exts0_enabled;
int exts1_enabled;
};
DEFINE_SPINLOCK(register_lock);
/*
* Register access functions
*/
static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
{
u64 ns;
u32 lo, hi;
lo = __raw_readl(®s->systime_lo);
hi = __raw_readl(®s->systime_hi);
ns = ((u64) hi) << 32;
ns |= lo;
ns <<= TICKS_NS_SHIFT;
return ns;
}
static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
{
u32 hi, lo;
ns >>= TICKS_NS_SHIFT;
hi = ns >> 32;
lo = ns & 0xffffffff;
__raw_writel(lo, ®s->systime_lo);
__raw_writel(hi, ®s->systime_hi);
}
/*
* Interrupt service routine
*/
static irqreturn_t isr(int irq, void *priv)
{
struct ixp_clock *ixp_clock = priv;
struct ixp46x_ts_regs *regs = ixp_clock->regs;
struct ptp_clock_event event;
u32 ack = 0, lo, hi, val;
val = __raw_readl(®s->event);
if (val & TSER_SNS) {
ack |= TSER_SNS;
if (ixp_clock->exts0_enabled) {
hi = __raw_readl(®s->asms_hi);
lo = __raw_readl(®s->asms_lo);
event.type = PTP_CLOCK_EXTTS;
event.index = 0;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
event.timestamp <<= TICKS_NS_SHIFT;
ptp_clock_event(ixp_clock->ptp_clock, &event);
}
}
if (val & TSER_SNM) {
ack |= TSER_SNM;
if (ixp_clock->exts1_enabled) {
hi = __raw_readl(®s->amms_hi);
lo = __raw_readl(®s->amms_lo);
event.type = PTP_CLOCK_EXTTS;
event.index = 1;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
event.timestamp <<= TICKS_NS_SHIFT;
ptp_clock_event(ixp_clock->ptp_clock, &event);
}
}
if (val & TTIPEND)
ack |= TTIPEND; /* this bit seems to be always set */
if (ack) {
__raw_writel(ack, ®s->event);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
/*
* PTP clock operations
*/
static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
u64 adj;
u32 diff, addend;
int neg_adj = 0;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
if (ppb < 0) {
neg_adj = 1;
ppb = -ppb;
}
addend = DEFAULT_ADDEND;
adj = addend;
adj *= ppb;
diff = div_u64(adj, 1000000000ULL);
addend = neg_adj ? addend - diff : addend + diff;
__raw_writel(addend, ®s->addend);
return 0;
}
static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
s64 now;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
spin_lock_irqsave(®ister_lock, flags);
now = ixp_systime_read(regs);
now += delta;
ixp_systime_write(regs, now);
spin_unlock_irqrestore(®ister_lock, flags);
return 0;
}
static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
{
u64 ns;
u32 remainder;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
spin_lock_irqsave(®ister_lock, flags);
ns = ixp_systime_read(regs);
spin_unlock_irqrestore(®ister_lock, flags);
ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
ts->tv_nsec = remainder;
return 0;
}
static int ptp_ixp_settime(struct ptp_clock_info *ptp,
const struct timespec *ts)
{
u64 ns;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
ns = ts->tv_sec * 1000000000ULL;
ns += ts->tv_nsec;
spin_lock_irqsave(®ister_lock, flags);
ixp_systime_write(regs, ns);
spin_unlock_irqrestore(®ister_lock, flags);
return 0;
}
static int ptp_ixp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
switch (rq->type) {
case PTP_CLK_REQ_EXTTS:
switch (rq->extts.index) {
case 0:
ixp_clock->exts0_enabled = on ? 1 : 0;
break;
case 1:
ixp_clock->exts1_enabled = on ? 1 : 0;
break;
default:
return -EINVAL;
}
return 0;
default:
break;
}
return -EOPNOTSUPP;
}
static struct ptp_clock_info ptp_ixp_caps = {
.owner = THIS_MODULE,
.name = "IXP46X timer",
.max_adj = 66666655,
.n_ext_ts = N_EXT_TS,
.pps = 0,
.adjfreq = ptp_ixp_adjfreq,
.adjtime = ptp_ixp_adjtime,
.gettime = ptp_ixp_gettime,
.settime = ptp_ixp_settime,
.enable = ptp_ixp_enable,
};
/* module operations */
static struct ixp_clock ixp_clock;
static int setup_interrupt(int gpio)
{
int irq;
gpio_line_config(gpio, IXP4XX_GPIO_IN);
irq = gpio_to_irq(gpio);
if (NO_IRQ == irq)
return NO_IRQ;
if (irq_set_irq_type(irq, IRQF_TRIGGER_FALLING)) {
pr_err("cannot set trigger type for irq %d\n", irq);
return NO_IRQ;
}
if (request_irq(irq, isr, 0, DRIVER, &ixp_clock)) {
pr_err("request_irq failed for irq %d\n", irq);
return NO_IRQ;
}
return irq;
}
static void __exit ptp_ixp_exit(void)
{
free_irq(MASTER_IRQ, &ixp_clock);
free_irq(SLAVE_IRQ, &ixp_clock);
ixp46x_phc_index = -1;
ptp_clock_unregister(ixp_clock.ptp_clock);
}
static int __init ptp_ixp_init(void)
{
if (!cpu_is_ixp46x())
return -ENODEV;
ixp_clock.regs =
(struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
ixp_clock.caps = ptp_ixp_caps;
ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
if (IS_ERR(ixp_clock.ptp_clock))
return PTR_ERR(ixp_clock.ptp_clock);
ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock);
__raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
__raw_writel(1, &ixp_clock.regs->trgt_lo);
__raw_writel(0, &ixp_clock.regs->trgt_hi);
__raw_writel(TTIPEND, &ixp_clock.regs->event);
if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
goto no_master;
}
if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
goto no_slave;
}
return 0;
no_slave:
free_irq(MASTER_IRQ, &ixp_clock);
no_master:
ptp_clock_unregister(ixp_clock.ptp_clock);
return -ENODEV;
}
module_init(ptp_ixp_init);
module_exit(ptp_ixp_exit);
MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
MODULE_LICENSE("GPL");
